Facilitating mobility for a mobile station

ABSTRACT

Providing a mobility key for a communication session for a mobile station includes facilitating initiation of the communication session. A master key for the communication session is established, where the master key is generated at an authentication server in response to authenticating the mobile station. A mobility key is derived from the authentication key at an access node, where the mobility key is operable to authenticate mobility signaling for the communication session.

TECHNICAL FIELD

This invention relates generally to the field of communications and morespecifically to facilitating mobility for a mobile station.

BACKGROUND

A communication network may establish a communication session for amobile station. The communication session allows the mobile station tocommunicate with other endpoints. The mobile station may move to anotherlocation serviced by a different communication network. Accordingly,techniques are implemented to allow the next communication network tosupport the communication session.

Known techniques, however, are not efficient in certain situations. Itis generally desirable to have efficient techniques in certainsituations.

SUMMARY OF THE DISCLOSURE

In accordance with the present invention, disadvantages and problemsassociated with previous techniques for facilitating mobility for amobile station may be reduced or eliminated.

According to one embodiment of the present invention, providing amobility key for a communication session for a mobile station includesfacilitating initiation of the communication session. A master key forthe communication session is established, where the master key isgenerated at an authentication server in response to authenticating themobile station. A mobility key is derived from the authentication key atan access node, where the mobility key is operable to authenticatemobility signaling for the communication session.

Certain embodiments of the invention may provide one or more technicaladvantages. A technical advantage of one embodiment may be that amobility key may be derived from a master key. Deriving the mobility keymay provide for a more readily available key. Another technicaladvantage of one embodiment may be that a route may be optimized tobypass a home agent. Bypassing the home agent may provide for moreefficient communication.

Certain embodiments of the invention may include none, some, or all ofthe above technical advantages. One or more other technical advantagesmay be readily apparent to one skilled in the art from the figures,descriptions, and claims included herein.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and itsfeatures and advantages, reference is now made to the followingdescription, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a block diagram illustrating one embodiment of a systemoperable to facilitate mobility for a mobile station;

FIG. 2 is a call flow diagram illustrating one embodiment of a methodfor providing a mobility key for a communication session; and

FIG. 3 is a call flow diagram illustrating one embodiment of a methodfor optimizing a route for a communication session.

DETAILED DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention and its advantages are bestunderstood by referring to FIGS. 1 through 3 of the drawings, likenumerals being used for like and corresponding parts of the variousdrawings.

FIG. 1 is a block diagram illustrating one embodiment of a system 10operable to facilitate mobility for a mobile station. System 10 mayprovide a mobility key for a communication session for the mobilestation. To provide the mobility key, a master key for the communicationsession may be established. The mobility key may then be derived fromthe master key. System 10 may also provide route optimization for thecommunication session. The optimized route communicates the sessionalong a path that bypasses a home agent for the mobile station.

According to the illustrated embodiment, a mobile station 20 mayrepresent any suitable logic comprising software, hardware, other logic,or any suitable combination of the preceding operable to communicatewith a communication system. Mobile station 20 may comprise, forexample, a personal digital assistant, a cellular telephone, a mobilehandset, or any other device operable to communicate with system 10.

System 10 may operate to provide telephony services, such ascommunication sessions, for endpoints such as mobile station 20. Acommunication session may refer to an active communication betweenendpoints, measured from endpoint to endpoint. Information iscommunicated between endpoints during a communication session.Information may refer to data, text, audio, video, multimedia, othersuitable type of information, or any combination of the preceding.Information may be communicated in packets. A packet may comprise abundle of data organized in a specific way for transmission, and a framemay comprise the payload of one or more packets organized in a specificway for transmission. A packet-based communication protocol such asInternet Protocol (IP) or mobile IP may be used to communicate thepackets.

System 10 and mobile station 20 may utilize digital cellular protocolsand technologies for the communication sessions. Example digitalcellular protocols and technologies include those set by the Instituteof Electrical and Electronics Engineers, Inc. (IEEE) 802.11 standards,the Global System for Mobile communications (GSM) standards, theInternet Engineering Task Force (IETF) standards, or other standards.GSM standards may support technology such as general packet radioservice (GPRS) technologies, and IETF standards may support codedivision multiple access (CDMA) technologies.

According to the illustrated embodiment, system 10 includes a homenetwork 24 a, a foreign network 24 b, one or more gateways 28, and oneor more other networks 32 coupled as shown. According to the embodiment,networks 24 comprise communication networks that facilitatecommunications sessions for mobile station 20. A communication networkmay refer to a network that allows devices to communicate with eachother. A communication network may comprise all or a portion of a publicswitched telephone network (PSTN), a public or private data network, alocal area network (LAN), a metropolitan area network (MAN), a wide areanetwork (WAN), a global computer network such as the Internet, awireline or wireless network, a local, regional, or global communicationnetwork, an enterprise intranet, other suitable communication link, orany combination of the preceding.

Home network 24 a may represent a communication network at which mobilestation 20 is permanently registered, and foreign network 24 b mayrepresent a communication network in which mobile station 20 iscurrently located. According to the illustrated embodiment, each network24 comprises one or more base stations 40, one or more access nodes 42,a home agent 52, and an authentication server 56 coupled as shown.

A base station 40 provides mobile station 20 with wireless access tosystem 10. Base station 40 may include a base transceiver station and abase station controller. The base transceiver station communicatessignals to and from mobile station 20. The base station controllermanages the operation of the base transceiver station. The wireless linkbetween mobile station 20 and base station 40 is typically a radiofrequency link that may be cellular in network organization.

An access node 42 may represent a point of a network 24 that providesaccess to network 24, and may provide access services such as protocolconversion, packet encapsulation and decapsulation, or other service.Access node 42 may comprise any suitable arrangement of components, suchas one or more access routers 44, one or more local mobility anchors 48,or any combination of the preceding. As an example, an access node 42may include one or more access routers 44, but no local mobility anchors48. As another example, an access node 42 may include one or more accessrouters 44 and one or more local mobility anchors 48.

Access router 44 may represent any suitable logic comprising software,hardware, other logic, or any combination of the preceding operable toconnect asynchronous devices such as mobile station 20 to network 24.According to one embodiment, access router 44 may provide a point atwhich the Open Systems Interconnection (OSI) Model Layer 2 signalingmeets Layer 3 signaling for mobile station 20.

Local mobility anchor 48 may represent any suitable logic comprisingsoftware, hardware, other logic, or any combination of the precedingoperable to provide mobility management aggregation services for accessrouters 44. In general, an anchor may refer to a point of a network thatmanages roaming connections for a communication session. Local mobilityanchor 48 operates like an agent 52 from the viewpoint of access routers44, and operates like an access router 44 from the viewpoint of agent52. According to one embodiment, local mobility anchor 48 mayencapsulate and decapsulate traffic, such as data traffic.

A component of access node 42 may intercept and consume messagesdirected to another node. According to one embodiment, local mobilityanchor 48 may intercept a signaling message directed to another node,such as mobile station 20. A signaling message may refer to a messagethat includes an instruction to perform an operation to set up, manage,or tear down a communication session. A message may be directed to anode by having the address of the node as the destination address.

According to the embodiment, local mobility anchor 48 may intercept asignaling message that is directed to another node. Local mobilityanchor 48 may be programmed to intercept specific signaling messagesdirected to the other node. Local mobility anchor 48 may consume thesignaling message by performing the operation of the message, and notforwarding the message to the other node.

An agent 52 may represent any suitable logic comprising software,hardware, other logic, or any suitable combination of the precedingoperable to provide mobility management services for mobile station 20.Home agent 52 a of mobile station 20 may represent an agent thatmaintains the address of mobile station 20 and forwards packets tomobile station 20. According to one embodiment, home agent 52 maygenerate a master key, from which a mobility key may be derived. Themaster key and mobility key are described in more detail with referenceto FIG. 2. Foreign agent 52 b of mobile station 20 may represent anagent that provides home agent 52 a of mobile station 20 with a care-ofaddress to which packets for mobile station 20 node may be forwarded.

If mobile station 20 is in an area serviced by home agent 52 a, homeagent 52 a forwards traffic to the location address of mobile station20. If mobile station 20 moves to an area serviced by foreign agent 52b, foreign agent 52 b notifies home agent 52 a that mobile station 20has moved, and sends a care-of address for mobile station 20 to homeagent 52 a. Home agent 52 a forwards traffic to the care-of address.

Authentication server 56 may represent any suitable logic comprisingsoftware, hardware, other logic, or any suitable combination of thepreceding operable to provide services for authentication,authorization, accounting, or any suitable combination of the preceding.Authentication may refer to authenticating a mobile station 20.Authorization may refer to authorizing a level of service for mobilestation 20. Accounting may refer to tracking the usage of resources. Asan example, authentication server 56 may provide one, two, or three ofthe listed services.

A gateway 28 may represent any suitable logic comprising software,hardware, other logic, or any suitable combination of the precedingoperable to interconnect networks 24 and 32. Gateway 28 may performprotocol conversion. For example, gateway 28 may convert communicationsfrom the protocol of one network to the protocol of another network.According to one embodiment, gateway 28 may include a route optimizerthat provides route optimization. Route optimization is described inmore detail with reference to FIG. 3.

A network 32 may represent any suitable communication network. As anexample, network 32 a may represent a legacy network. As anotherexample, network 32 b may represent a Internet Protocol (IP) networkthat operates according to the Internet Protocol. As yet anotherexample, network 32 c may represent an intranet that includes acorrespondent node 60 engaged in a communication session with mobilestation 20. Correspondent node 60 may represent any suitable logiccomprising software, hardware, other logic, or any suitable combinationof the preceding operable to communicate with mobile station 20.

A component of system 10 may include an interface, logic, memory, or anysuitable combination of the preceding. As used in this document,“interface” refers to any suitable structure of a device operable toreceive input for the device, send output from the device, translateinput or output or both, or perform any combination of the preceding,and may comprise one or more ports. Logic manages the operation ofmodule, and may comprise any suitable hardware, software, or combinationof hardware and software. For example, logic may include a processor. Asused in this document, “processor” refers to any suitable deviceoperable to execute instructions and manipulate data to performoperations.

As used in this document, “memory” refers to any structure operable tostore and facilitate retrieval of information used by a processor, andmay comprise Random Access Memory (RAM), Read Only Memory (ROM),magnetic drives, disk drives, Compact Disk (CD) drives, Digital VideoDisk (DVD) drives, removable media storage, any other suitable datastorage device, or a combination of any of the preceding.

The mobility state of mobile station 20 may be maintained by access node42 and other nodes of system 10 that facilitate a communication sessionfor mobile station 20, such as home agent 52 a and gateways 28. Themobility state may be described by a binding cache entry, a bindingupdate list, a data flow cache entry, other mobility descriptor, or anycombination of the preceding.

A binding cache entry records information for routing packets to mobilestation 20. For example, a binding cache entry may record an address,such as home address or a care-of address or both, to which packets formobile station 20 may be forwarded. The binding cache entry may includeother information about mobile station 20, such as the state of thecommunication session of mobile station 20. A binding update listrecords information for routing packets to correspondent node 60. Forexample, a binding update list may record addresses for access routersor gateways used by correspondent node 60. A data flow cache entry mayrefer to information learned from received data flows.

Messages may provide or request mobility state information. For example,a binding update from a sender provides updated routing informationabout the sender. A binding acknowledgement confirms that a bindingupdate was received. A binding request from a sender to a receiverrequests that the receiver send a binding update to the sender. Abinding delete from a sender to a receiver requests that the receiverremove the binding cache entry associated with the sender.

Modifications, additions, or omissions may be made to system 10 withoutdeparting from the scope of the invention. The components of system 10may be integrated or separated according to particular needs. Moreover,the operations of system 10 may be performed by more, fewer, or othermodules. For example, the operations of access router 44 and localmobility anchor 48 may be performed by one module, or the operations ofagent 52 a may be performed by more than one module. Additionally,operations of system 10 may be performed using any suitable logiccomprising software, hardware, other logic, or any suitable combinationof the preceding. As used in this document, “each” refers to each memberof a set or each member of a subset of a set.

FIG. 2 is a call flow diagram illustrating one embodiment of a methodfor providing a mobility key for a communication session. To provide themobility key, a master key for the communication session may beestablished. The mobility key may then be derived from the master key.

The method begins at step 100, where mobile station 20 initiates accessto foreign network 24 b through foreign access router 44 e of network 24b. Access router 44 e sends an authentication request to foreignauthentication server 56 b at step 104. An authentication request mayrefer to a message that requests authentication for a node. The messagemay also request other services such as authorization, accounting, otherservice, or any combination of the preceding.

Authentication server 56 b relays the authentication request to homeauthentication server 56 a at step 108. Authentication server 56 aauthenticates mobile station 20 at step 112. According to oneembodiment, home authentication server 56 a authenticates mobile station20 according to an authentication key. A key may refer to an encryptionkey or decryption key. An authentication key may refer to a key that isused to verify the authenticity of a mobile station 20. According to oneembodiment, a mobile station-authentication server (MS-AS) key may beused to authenticate mobile station 20. An MS-AS key may refer to anauthentication key shared between mobile station 20 and homeauthentication server 56 a.

Authentication server 56 a derives a master key at step 116. In general,a second key may be derived from a first key by applying a procedure oralgorithm to the first key to yield the second key. A master key mayrefer to an authentication key that is used to authenticate mobilestation 20 for a particular time. For example, a master key comprising amaster session key may refer to an authentication key that is used toauthenticate mobile station 20 for a particular communication session.According to one embodiment, home authentication server 56 a derives amaster session key from the MS-AS key.

Authentication server 56 a sends an authentication reply to foreignauthentication server 56 b at step 120. According to one embodiment, theauthentication reply includes the master session key. Homeauthentication server 56 a sends an authentication update to home agent52 a at step 124. The update includes an application key. An applicationkey may refer to an authentication key that is used to authenticatemobile station 20 for a particular application, such as a mobility oraccess application. According to one embodiment, the application keycomprises a mobile IP application key derived from the master sessionkey for the duration of the registration process. Foreign authenticationserver 56 a relays the authentication reply to access router 44 a atstep 128. The reply includes the master session key.

Access router 44 e derives application keys from the master key at step132. According to one embodiment, a mobility key and an access key maybe derived from the master session key. A mobility key may refer to anauthentication key that may be used to provide mobility management, suchas Layer 3 mobility management. The key may be used to authenticatesignaling among network nodes during a handoff procedure. According tothe embodiment, a mobile station-network node key may be used toauthenticate signaling to the network node in order to send signalingmessages to the network node. For example, a mobile station-home agent(MN-HA) key may be used to authenticate signaling to home agent 52 a.The MN-HA key may be used on the behalf of mobile station 20 to send asignaling message, such as a binding update, to home agent 52 a.

An access key may refer to an authentication key that is used to provideaccess authentication, such a authentication for example Layer 2 access.According to the embodiment, the derived access key may comprise amobile station-access router (MS-AR) Layer 2 key that provides Layer 2access while access router 44 is facilitating the communication sessionfor mobile node 20.

Access authentication is performed at step 136 using the derivedmobility key. According to one embodiment, the derived mobility key maycomprise the MS-AR key. After performing access authentication, themethod terminates.

Modifications, additions, or omissions may be made to the method withoutdeparting from the scope of the invention. The method may include more,fewer, or other steps. Additionally, steps may be performed in anysuitable order without departing from the scope of the invention.

FIG. 3 is a call flow diagram illustrating one embodiment of a methodfor optimizing a route for a communication session. The method mayoptimize a communication path by bypassing home agent 52 a. The methodmay be performed by a first embodiment, a second embodiment, or othersuitable embodiment. According to the first embodiment, access node 42includes one or more access routers 44. According to the secondembodiment, access node 42 includes one or more access routers 44 andone or more local mobility anchors 48.

The method begins at step 200, where correspondent node 60 sends packetsto a route optimizer. The route optimizer may be located at gateway 28or other suitable node of system 10. The route optimizer determineswhether route optimization is to be performed at step 204. Thedetermination may be made by establishing the non-optimized route anddetermining whether bypassing home agent 52 a would optimize the route.In this example, the route optimizer determines that route optimizationis to be performed.

The route optimizer sends a binding request to home agent 52 a at step208. The binding request requests that a receiver sends a binding updateof mobile station 20 to the route optimizer, and may be sent as acontrol message. Home agent 52 a has a binding cache entry for mobilestation 20 at step 212, and tunnels the binding request to access node42 a at step 216.

Access node 42 a consumes the binding request at step 220, and sends abinding update at step 224. The binding update includes the home addressof access node 42 a, and may be sent as a control message. Steps 220 and224 may be performed by the first embodiment, the second embodiment, orother suitable embodiment. According to the first embodiment, accessrouter 44 a consumes the binding request at step 220, and sends thebinding update at step 224. According to the second embodiment, localmobility anchor 48 a consumes the binding request at step 220, and sendsthe binding update at step 224.

The route optimizer creates a binding cache entry for mobile station 20at step 228. The binding cache entry records access node 42 a as thehome address of mobile station 20. Step 228 may be performed by thefirst embodiment, the second embodiment, or other suitable embodiment.According to the first embodiment, the recorded access node 42 a isaccess router 44 a. According to the second embodiment, the recordedaccess node 42 a is local mobility anchor 48 a. The route optimizersends a binding acknowledgement to access node 42 a at step 232. Thebinding acknowledgement includes the home address of the routeoptimizer. Access node 42 a updates its binding update list at step 236.The binding update list records that correspondent node 60 communicatesthrough the route optimizer.

Mobile station 20 sends a packet destined for correspondent node 60 toaccess node 42 a at step 240. Access node 42 a checks its binding updatelist at step 244. The binding update list indicates that correspondentnode 60 may be reached through the route optimizer. Access node 42 atunnels the packet to the route optimizer at step 248. Steps 244 and 248may be performed by the first embodiment, the second embodiment, orother suitable embodiment. According to the first embodiment, accessrouter 44 a receives the packet from mobile station 20, and tunnels thepacket to the route optimizer. According to the second embodiment,access router receives the packet from mobile station 20, and tunnelsthe packet to local mobility anchor 48. Local mobility anchor identifiesthe route optimizer, and tunnels the packet to the route optimizer. Theroute optimizer forwards the packet to correspondent node 60 at step252.

Correspondent node 60 sends a packet destined for mobile station 20 tothe route optimizer at step 256. The route optimizer checks its bindingcache entry for mobile station 20 at step 260, and tunnels the packet toaccess node 42 a according to the entry at step 264. Steps 260 and 264may be performed by the first embodiment, the second embodiment, orother suitable embodiment. According to the first embodiment, thebinding cache entry at the route optimizer instructs the route optimizerto tunnel the packet directly to access router 44 a. According to thesecond embodiment, the binding cache entry at the route optimizerinstructs the route optimizer to tunnel the packet to local mobilityanchor 48 a. The binding cache entry at local mobility anchor 48 a has abinding cache entry for mobile station instructs local mobility anchor48 a to tunnel the packet to access router 44 a. Access node 42 forwardsthe packet to mobile station at step 268.

Modifications, additions, or omissions may be made to the method withoutdeparting from the scope of the invention. The method may include more,fewer, or other steps. Additionally, steps may be performed in anysuitable order without departing from the scope of the invention.

Certain embodiments of the invention may provide one or more technicaladvantages. A technical advantage of one embodiment may be that amobility key may be derived from a master key. Deriving the mobility keymay provide for a more readily available key. Another technicaladvantage of one embodiment may be that a route may be optimized tobypass a home agent. Bypassing the home agent may provide for moreefficient communication.

While this disclosure has been described in terms of certain embodimentsand generally associated methods, alterations and permutations of theembodiments and methods will be apparent to those skilled in the art.Accordingly, the above description of example embodiments does notconstrain this disclosure. Other changes, substitutions, and alterationsare also possible without departing from the spirit and scope of thisdisclosure, as defined by the following claims.

1. A method for providing a mobility key for a communication session,comprising: facilitating initiation of a communication session for amobile station; establishing a master key for the communication session,the master key generated at an authentication server in response toauthenticating the mobile station; and deriving a mobility key from theauthentication key at an access node, the mobility key operable toauthenticate mobility signaling for the communication session.
 2. Themethod of claim 1, wherein: the mobility key comprises a mobilestation-network node key, the mobile station-network node key operableto authenticate mobility signaling to a network node of thecommunication network; and further comprising: authenticating a signalmessage sent to the network node using the mobile station-network nodekey.
 3. The method of claim 1, wherein: the mobility key comprises amobile station-home agent, the mobile station-home agent key operable toauthenticate mobility signaling to a home agent; and further comprising:authenticating a binding update sent to the home agent using the mobilestation-home agent key.
 4. A node for determining a mobility key for acommunication session, comprising: an interface operable to receive aplurality of packets; and logic coupled to the interface and operableto: facilitate initiation of a communication session for a mobilestation; establish a master key for the communication session, themaster key generated at an authentication server in response toauthenticating the mobile station; and derive a mobility key from theauthentication key, the mobility key operable to authenticate mobilitysignaling for the communication session.
 5. The node of claim 4,wherein: the mobility key comprises a mobile station-network node key,the mobile station-network node key operable to authenticate mobilitysignaling to a network node of the communication network; and a signalmessage sent to the network node is authenticated using the mobilestation-network node key.
 6. The node of claim 4, wherein: the mobilitykey comprises a mobile station-home agent, the mobile station-home agentkey operable to authenticate mobility signaling to a home agent; and abinding update sent to the home agent is authenticated using the mobilestation-home agent key.
 7. The node of claim 4, wherein: the mobilitykey comprises: a mobile station-network node key, the mobilestation-network node key operable to authenticate mobility signaling toa network node of the communication network; and a mobile station-homeagent, the mobile station-home agent key operable to authenticatemobility signaling to a home agent; and a signal message sent to thenetwork node is authenticated using the mobile station-network node key;and a binding update sent to the home agent is authenticated using themobile station-home agent key.
 8. A system for providing a mobility keyfor a communication session, comprising: means for facilitatinginitiation of a communication session for a mobile station; means forestablishing a master key for the communication session, the master keygenerated at an authentication server in response to authenticating themobile station; and means for deriving a mobility key from theauthentication key at an access node, the mobility key operable toauthenticate mobility signaling for the communication session.
 9. Anetwork for providing a mobility key for a communication session,comprising: an authentication server operable to: facilitate initiationof a communication session for a mobile station by authenticating themobile station; and generate a master key for the communication sessionin response to authenticating the mobile station; and an access node incommunication with the authentication server and operable to: derive amobility key from the authentication key, the mobility key operable toauthenticate mobility signaling for the communication session.
 10. Thenetwork of claim 9, wherein: the mobility key comprises a mobilestation-network node key, the mobile station-network node key operableto authenticate mobility signaling to a network node of thecommunication network; and further comprising the network node operableto: authenticate a signal message using the mobile station-network nodekey.
 11. The network of claim 9, wherein: the mobility key comprises amobile station-home agent, the mobile station-home agent key operable toauthenticate mobility signaling to a home agent; and further comprisingthe home agent operable to: authenticate a binding update using themobile station-home agent key.
 12. A method for optimizing a route for acommunication session, comprising: facilitating initiation of acommunication session between a mobile station and a correspondent node,the initiation facilitated at a route optimizer; sending a bindingrequest to a home agent of the mobile station, the binding requestrequesting a binding update for the mobile station; receiving a bindingupdate in response the binding request, the binding update identifyingan access node address of an access node corresponding to the mobilestation; creating a binding cache entry for the mobile station, thebinding cache entry recording the access node address; and bypassing thehome agent to facilitate continuation of the communication session. 13.The method of claim 1, wherein bypassing the home agent to facilitatecontinuation of the communication session further comprises:establishing a tunnel between the route optimizer and the access nodeusing the access node address; and tunneling a packet to the accessnode.
 14. The method of claim 1, wherein a gateway associated with thecorrespondent node comprises the route optimizer.
 15. A route optimizerfor optimizing a route for a communication session, comprising: logicoperable to: facilitate initiation of a communication session between amobile station and a correspondent node; and an interface coupled to thelogic and operable to: send a binding request to a home agent of themobile station, the binding request requesting a binding update for themobile station; receive a binding update in response the bindingrequest, the binding update identifying an access node address of anaccess node corresponding to the mobile station; the logic furtheroperable to: create a binding cache entry for the mobile station, thebinding cache entry recording the access node address; and facilitatecontinuation of the communication session along a path that bypasses thehome agent.
 16. The route optimizer of claim 15, the logic furtheroperable to facilitate continuation of the communication session along apath that bypasses the home agent by: establishing a tunnel to theaccess node using the access node address; and tunneling a packet to theaccess node.
 17. The route optimizer of claim 15, wherein a gatewayassociated with the correspondent node comprises the route optimizer.18. The route optimizer of claim 15, wherein: the logic further isoperable to facilitate continuation of the communication session along apath that bypasses the home agent by: establishing a tunnel to theaccess node using the access node address; and tunneling a packet to theaccess node; and a gateway associated with the correspondent nodecomprises the route optimizer.
 19. A system for optimizing a route for acommunication session, comprising: means for facilitating initiation ofa communication session between a mobile station and a correspondentnode, the initiation facilitated at a route optimizer; means for sendinga binding request to a home agent of the mobile station, the bindingrequest requesting a binding update for the mobile station; means forreceiving a binding update in response the binding request, the bindingupdate identifying an access node address of an access nodecorresponding to the mobile station; means for creating a binding cacheentry for the mobile station, the binding cache entry recording theaccess node address; and means for bypassing the home agent tofacilitate continuation of the communication session.
 20. A network foroptimizing a route for a communication session, comprising: a routeoptimizer operable to: facilitate initiation of a communication sessionbetween a mobile station and a correspondent node; send a bindingrequest requesting a binding update for the mobile station; a home agentof the mobile station, the home agent in communication with the routeoptimizer and operable to: receive the binding request; and send abinding update in response the binding request, the binding updateidentifying an access node address of an access node corresponding tothe mobile station; the route optimizer further operable to: receive thebinding update; create a binding cache entry for the mobile station, thebinding cache entry recording the access node address; and facilitatecontinuation of the communication session by bypassing the home agent.21. The network of claim 20, the route optimizer further operable tofacilitate continuation of the communication session by bypassing thehome agent by: establishing a tunnel between the route optimizer and theaccess node using the access node address; and tunneling a packet to theaccess node.
 22. The network of claim 20, wherein a gateway associatedwith the correspondent node comprises the route optimizer.
 23. A methodfor consuming a message, comprising: receiving a signaling message at anaccess node, the signaling message directed to a mobile station, thesignaling message comprising an instruction to perform an operation fora communication session for the mobile station; intercepting thesignaling message; performing the operation for the communicationsession; and consuming the signaling message, the signaling messagefailing to reach the mobile station.
 24. The method of claim 23,wherein: receiving the signaling message at the access node furthercomprises: receiving the signaling message comprising a binding requestfor the mobile station; and performing the operation for thecommunication session further comprises: sending a binding updatecomprising an address corresponding to the access node.
 25. The methodof claim 23, wherein receiving the signaling message at the access nodefurther comprises: receiving the signaling message at a local mobilitymanager of the access node.
 26. An access node of a communicationnetwork, comprising: an interface operable to: receive a signalingmessage, the signaling message directed to a mobile station, thesignaling message comprising an instruction to perform an operation fora communication session for the mobile station; and logic operable to:intercept the signaling message; perform the operation for thecommunication session; and consume the signaling message, the signalingmessage failing to reach the mobile station.
 27. The access node ofclaim 26, the logic further operable to: receive the signaling messageat the access node by: receiving the signaling message comprising abinding request for the mobile station; and perform the operation forthe communication session by: sending a binding update comprising anaddress corresponding to the access node.
 28. The access node of claim26, the logic further operable to receive the signaling message at theaccess node by: receiving the signaling message at a local mobilitymanager of the access node.